We use the Prettier recommended with a few additional guidelines.
Example
<body class="some-class">
<!-- ALWAYS use quotation marks when setting attribute, double quotes are preferred -->
<img src="relative/path.png" alt="Always use alt text or an empty alt tag" />
<!-- NOTE: No info is better than bad info. Almost ALWAYS! -->
<form action="#" method="POST">
<!--Always use as specific a control as possible-->
<input type="number" readonly value="1" />
<!--Keyword attributes are ok-->
<input type="submit" value="Submit Me!" />
</form>
<p>
Paragraph tags are important for paragraphs, even if the browser will let
you just use divs.
</p>
</body>